<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>伪类</title>
		<style type="text/css">
			input:focus{
				background-color: blueviolet;
			}
			input:hover{
				background-color: #FF0000;
			}
			button:active{
				background-color: #256FFF;
				color: white;
			}
		</style>
	</head>
	<body>
	<input  type="password" name=""/>
	<button type="button">提交</button>
	
	</body>
</html>